7.Send them snacks for the after-after-party.

The newlyweds are usually too busy to eat at the reception, which means that once the after-party has shut down, they're likely going to be starving. Be the one to save them with comfort food (pizza) and celebratory drinks (champagne).

8.But if you'd rather give money, don't feel pressured to give more than you can afford.

The "guideline" for how much you should give is what you'd spend on your own plate at a really nice dinner. (Which is not the same as what the couple is spending on your plate at the reception.) If that's $50, that's OK! You don't need to drop hundreds of dollars just because it's a ~fancy~ wedding.

Instead of staying at a hotel suggested by the couple, check the local availability on Airbnb. You can filter your search by price, location, and how much space you'll need (an entire place, a private room, or a shared room) to get exactly what you want for a price that works.

It's not a guarantee, but many airlines restock their flights on Monday evenings. By Tuesday evening, airlines have matched their competitors' prices, so the largest amount of cheap flights are available at that time.

Also, make sure you clear your cache before searching for flights. If a website can detect that you've been searching for a specific flight, they may raise the prices on your search.

17.Rent a dress instead of buying.

Rent the Runway gives $25 off your first order, and you can shop by price. They'll send you two size options (for no additional cost) and you just send it back in a prepaid mailing envelope three days after receiving the dress.